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(No Mom. C. HLFIELD.

ENGRAVINGMAGHINE. V No. 402,316. Patented Apr. 30. 1889.

2 Sheets-Sheet 1.

N. PFIERS, Pholmmhngnpher. Wahlngfim, n. c.

(No Model.) 2 sheets-sheet 2. C. H. FIELD.

- p 'BNGRAVING MACHINE. I

N0. 402,316. Patented Apr. '30, 1889..

N. PETERS. Pmwum m m. Wnhmgmn. cu;

UNIT D STATES PATENT OFFICE.

CHARLES H. FIELD, OF PROVIDENCE, RHODE ISLAND.

ENGRAVING- MACHINE.

SPECIFICATION forming part of Letters Patent No. 402,316, dated April 30, 1889.

To all whom it may concern;

Providence, in the State of Rhode Island, have invented new and useful Improvements in Engraving-Machines, of which the followof the said pattern-block have a raised surface, which is acted upon by means of a friction-wheel, so that when said friction-wheel is in contact with the raised surface on the revolving pattern-block the tool-post is thrown backward and the graver withdrawn fromcontact with the plate which is .being engraved; but when said friction-wheel is not riding upon said raised surfaces the graver will operate in engraving. The raised surfaces in the pattern-block therefore cause portions of the plate or watch-case to be reserved or plain, with any desired outline for a plain finish, or for the introduction of handengraving; but the mechanical action of the pattern-block upon the graver, through the nature of the mechanism employed, is liable to a certain degree of imperfect action, and.

it is the object of my present invention to still further improve the rosette-machine by an improved application of electricity to the same, so as to produce a much better class of work than heretofore, and with much less expense for patterns; and my invention consists in the employment of two separate and distinct electric currents, one acting through a main electric circuit to energize an electromagnet for suitably operating the graver, and the other, which is a weaker current, acting through a separate electric circuit, including a pattern-plate and tracing-point, to energize an electro-magnet which is adapted to cause the opening or closing of the main electric circuit, with means for causing the proper Be it known that I, CHARLES H. FIELD, of,

Application filed Novemher 9, 1888. Serial No. 290,404- (No model.)

corresponding traverse of the graver and tracing point, and by the employment of the said separate and distinct electric currents, acting through separate and distinct electric circuits, in an engraving-machine, I am able to greatly reduce the spark at the breakingcontact of the tracing-point with the patternplate, and thus the wear and waste at the edges of the pattern-plate can be reduced to the least possible amount.

My invention also consists in an improve ment for transmitting the lateral movement of the graver correspondingly to the tracing point at the pattern-plate.

It also consists in the hinged connection of the electromagnet in the main electric circuit with the graver-carriage, whereby the said magnet can be readily turned to a rearward position to permit the required backward movement of the graver upon the completion of the Work.

Figure 1 is a plan view of a rosette-engine provided with myimprovements, showing the electric connections with the same. Fig. 2 is a plan View showing the gravencarriage with the magnet turned to its rearward position to permit a backward movement of the gr ver. Fig. 3 is an elevation of the engine with some of the parts shown in Fig. 1 removed, in order to plainly illustrate my improvement. Figs. 4 and 5 are enlarged detail views illustrating the adjustable cam for transmitting movement from the traversing block to the tracingpoint of the pattern-plate.

In the accompanying drawings, A denotes the bed-plate of the machine; B, the vibrating frame; 0, the work shaft or spindle, which is provided with means for holding the chuck d, on the end of which the piece of metal'to be engraved or ornamented is secured by cement.

D denotes the rosette-shaft, which is mounted in bearings at the lower end of the frame B, parallel with the work-shaft.

The graver-carriage standard is shown at E, and is secured to the bed of the machine by means of a slot in its base and a clamping-screw at 'i, which occupies a curved slot in the bed-plate, thus admitting of the adj ustability of the standard with relation to the end of the work-spindle.

The traversing screw is shown at F, provided with a hand-crank, a gear, and springpawl, and is connected with driving-gearing mounted on the frame by means of a shaft having universal joints, so that the screw may be revolved regardless of the particular position of the standard The spring-pawl admits of the disconnection of the gearingfrom the screw, which can then be revolved by its hand-crank, as set forth in my said former patent.

G denotes the traversing block dovetailed to the standard and connected with the traversing screw.

H denotes the graver-carriage, which is secured to the traversing block by means of a hollow vertical pivot at its front end, and the dovetailed slide I, which is fitted into a recess in the traversing block, so that said slide may move to and fro in aline at right angles to the axis of the traversing screw. The graver-carriage II embraces a bed, m, a toolpost, 01, a slide, it, on which the tool post is mounted, and a hand-lever, w, pivoted to the bed on and connected by a spiral spring to the slide n, so that the spring may be controlled for forcing the tool-post forward, or so that the slide may be released from the action of the spring when the tool-post is to be withdrawn pending adjustment.

The parts thus referred to are not materially unlike those shown in my said former patent.

'1 denotes the insulated metallic patternplate attached to the gear J, which engages with a gear, K, of equal size upon the workshaft C. The spaces of the metallic pattern are filled with any suitable non-conducting material, and suitable electric connection may be made with the pattern-plate by means of the insulated spring I), which bears lightly against the edge of the pattern plate T. From the electro-magnet L connection is made with one pole of the galvanic cell M by means of the insulated wire 0, the opposite pole of the cell M being connected with the insulated tracing-point N by means of the insulated wire cl, and from the magnet L connection is made with the insulated spring I) by means of the insulated wire 6, thus, with the raised portions of the pattern, completing an elec-- tric circuit, and on account of the comparatively weak current required to attract the armature f of the magnet the breaking contact of the electric circuit at the elevated portions of the pattern, will produce a comparatively faint spark, thus occasioning but slight waste or wear. The armature f is attached transversely of the pivoted lever g, which is arranged to vibrate between the points of the screws h h at the upper end of the standard a, and is drawn away from the face of the magnet by means of the spring j, and when the armature fis drawn to the face of the magnet L the main electric circuit around the magnet 0 will be closed through the contact of the screw h and lever g, and when the said armature is drawn back from the magnet by the resilient action of the spring j the said circuit will be broken.

P denotes a dynamo or other generative source of electricity for operating the main circuit, and from one pole, s, of the dynamo electric connection is made with the bindingscrew by means of the insulated wire I, and from the opposite binding-screw, k, electric connection is made with the magnet O by means of the insulated wire 0, which passes upward through the perforated pivot 19, and thence to the insulated spring g upon the graver-carriage, andfrom the opposite insulated spring, q, upon the .g1'aver-carriage electric connection is made with the other pole, s, of the dynamo by means of the insulated wire 0, which passes from the said spring downward through the perforated pivot 19, and thence to the dynamo.

The terminals 25 f of the winding wire of the magnet O of the main circuit are arranged upon the surface of the cross-bar u, so that when the magnet O is turned downward to its proper normal seat upon the graver-carriage the terminals t 25 will strike the springs q g, respectively, and thus properly complete the main electric circuit from the dynamo or other equivalent generative source of electricity.

The armature Q of the magnet O is attached to the slide a of the graver-carriage, so as to move therewith, and the magnet O is hinged to the graver-carriage at the point 1; in order that the said magnet can be turned away from its armature to provide for the backward movement of the graver c from the work by means of the hand-lever w. The insulated tracing-point N, which moves diametrically of the revolving pattern-plate T, is held to press lightly against the face of the pattern-plate, and is arranged at the upper end of the sliding bar I), which is held in the guide a, secured to the frame B. The bar I) is jointed to one end of the lever e, the said lever being pivoted at the point g to the arm f, which projects from the frame B and is provided at its other end with the friction-roller 0". To the inner end of the traversing block G is attached the adjustable plain cam S, which maybe c011- structed as shown in side elevation in Fig. 4 and end view in Fig. 5, and which is provided with the comparatively broad bearing-surface i and with the slot j, which is adapted to receive the screw 70, by means of which the cam is attached to the traversing block. The cam S is to be set in such inclined position as will, by acting upon the friction-roller 0" of the lever e, serve to produce the corresponding movement of the tracing-point N from the outer margin of the pattern to its center, with that of the graver c from the outer margin of the watch-case or other piece of Work to its center, and the cam S, by reason of its comparatively broad face 'i, is adapted to the various positions of the graver-carriage standard E upon the bed-plate A.

The employment of two separate and distinctcurrents of electricity, as above described, in an engraving-machine, is a great improvement over those engraving-machines in which a branch of the main electric circuit is caused to pass to a relay-magnet through a very fine wire, for the reason that by the use of the separate electric current and circuit a Weak quantity current can be employed, Whereas by interposing a fine wire with the main electric circuit, a current of 'greater'intensity will be producedgthrough the tracingpoint, thus tending to increase the damaging effect of the comparatively faint spark thus produced from the main current.

I claim as my invention- 1. The combination, with a. graver and graver-carriage, of a main electric circuit and an electro-magnet adapted to operate the graver, a separate electric circuit, including a pattern-plate, tracing-point, and electromagnet for closing or breaking the main electric circuit, and meansfor imparting traversing movement to the gr'aver and tracing-point, substantially as and for the purpose specified.

2. The combination, with the graver and graver-carriage, of a main electric circuit and electro-magnet adapted to operate the graver,

' the separate electric circuit, including a pat- Witnesses:

JOHN S. LYNCH, SooRATEs ScHoLFIELn. 

